1. Field of the Invention
The present invention relates to a phthalocyanine compound, particularly a di-(4-vinylimidazole) metal phthalocyanine compound, a composition comprising the same and a preparation method thereof, and more particularly to a phthalocyanine compound which has an excellent UV (Ultraviolet)-blocking effect together with low surface resistance and is prepared by charging a powder phase with nitrogen, not by dissolving raw materials in an organic solvent as in the prior art.
2. Description of the Background
A phthalocyanine is a macrocyclic compound having an alternating nitrogen atom-carbon atom ring structure. Recently, phthalocyanine compounds have been widely used in various fields, because they have high visible light transmittance and a high infrared ray shielding effects, are excellent in the ability to selectively filter light, particularly in the near infrared region, and show excellent heat resistance, light resistance and weather resistance.
For example, Korean Patent Laid-Open Publication No. 2003-96052 discloses a phthalocyanine compound represented by the following Formula 1, which can be advantageously used for plasma display front panels:

where, Z2, Z3, Z6, Z7, Z10, Z11, Z14 and Z15 each represents SR1, SR2, OR3 or a halogen atom, provided that at least one thereof represents SR2; and Z1, Z4, Z5, Z8, Z9, Z12, Z13 and Z16, each represents NHR4, NHR5, SR1, SR2, OR3 or a halogen atom, provided that at least one thereof represents NHR5 and that at least four thereof represent OR3; wherein R1 represents an optionally substituted phenyl group, an alkyl group or an optionally substituted C1-C20 alkyl group; R2 represents a phenyl group optionally substituted with a C1-C20 alkoxy group; R3 and R4 each represent an optionally substituted phenyl group, an alkyl group or an optionally substituted C1-C20 alkyl group; R5 represents an optionally substituted C1-C20 alkyl group; R1, R2, R3, R4 and R5 may be the same or different from each other; and M represents a non-metal, a metal, a metal oxide or a metal halide.
The phthalocyanine compounds having the above-described structure can be easily obtained by adding phthalic anhydride, phthalimide, dicyanobenzene, 1,2-dicyanoisoindoline or the like to urea and a metal and allowing the mixture to react at high temperature while blocking the introduction of oxygen during the reaction or using a high-boiling-point solvent.
However, such phthalocyanine compounds have problems in that they have high surface resistance, are used as a near infrared light absorber in a limited wavelength region and show low light absorptivity. In addition, such phthalocyanine compounds have problems in that they have a relatively low reactivity and a low solubility in a solvent, and thus are prepared in low yield. Furthermore, they show low coating efficiency when being used to prepare films and, in addition, do not show sufficient reactivity in a gelling process.